Slide 1

Submitted to:- Dr. D.J. Ghodasara Associate Professor, Dept. of vet. Pathology, Anand

Submitted by:- Undhad Vishal M.V.Sc. Scholar Dept. of vet. PathologyMast Cell Tumor

Mast cell

Mast cell or mastocyte is a normal component of connective tissue Mast cell are quite pleomorphic & nucleus are round or ovoid & basophilic granulesCytoplasmic basophilic granules physiological active & two components secretes 1. Histamine 2. Heparin

Mast cell

Eosinophile

Basophile

Mastocytoma/Mastoma in Dog

Mastocytoma is benign tumor of tissue mast cells German mast means fattend or stuffed cyte comes from Greek kytos means hollow cell

EtiologyGenetic predisposegolden/red coat color Chronic immune over-stimulation that occurs in dogs with allergies or other inflammatory conditions. There may be environmental factors, viruses or other undetermined contributors. Middle age to older dogs are more likely to develop MCT's

Incidence6% of all tumors & 13% of skin tumors in dogAge:- 8 yearsBreed:- Boxer & Pug more commonSex:- Both sex same incidence Clinical characteristicsGastric & duodenal ulcerFocal glomarulonephritisDefect in immune responseDefective blood coagulation

SitesHindquarter are most common (thigh, groin, scrotum)

Gross morphology1 to 10 cm diameterTumor present in dermisCut surface is grayish whiteSome time well capsulated grossly

FIGURE 1. A large pedunculated cutaneous mast cell tumor on a mixed-breed female dog. FIGURE 2. female Shar-Peis at left hindlimb more aggressive and invasive mast cell tumors with invole mammary tissues. FIGURE 3. A hyperpigmented raised lesion involving the left lateral thigh region.FIGURE 4. A raised erythematous mucocutaneous lesion involving the preputial orifice on a castrated male pug.

A large and invasive mast cell tumor involving the left tarsus in a female Labrador

Mast cell tumor on the hock of a 6-year-old boxer

Mast cell tumor on left hind limb of a dogLarge Mast cell tumor on the right fore limb of a dog

Mast cell tumor on the inner thigh of a dog

Mast cell tumor of the paw

Mast cell tumor of the paw

Multiple cutaneous mast cell tumors with peritumoral edema and bleeding.

Preputial mast cell tumor with peritumoral edema, bruising and erythema.

Muzzle mast cell tumor.

Clinical GradingGradeIOne tumor confined to the dermis without regional lymph node involvementIIOne tumor confined to the dermis with regional lymph node involvementIIIMultiple dermal tumors or large infiltrating tumor with or without regional lymph node involvementIVAny tumor with distant metastases or recurrence with metastases

Histologic featuresBased on degree of differantiation

Cell charactersMatureIntermediateAnaplasticCell shapeRound to avoidRound to avoidPleomorphicCell sizeUniformVaryVaryCytoplasmic borderWell definedIndistinctIndistinct

NucleiUniformly sphericalLarge, slight vesicularLarge, vesicular & irregular

Mitotic figuresRarePresentNumerousCell arrangementLoosely in cord or nestCordLarge sheets

Presents of eosinophiles due to some immunological reactionFocal area of collagen degeneration are presentVascular lesion like hyalinization & fibrinoid degeneration of small arteriolesIn 10% cases focal accumulation of lymphocyte & plasma cells

HematologyIncrease serum gamma globulinRarely circulating mast cells

Growth & metastasisLeast potentially malignantCorrelation between degree of maturity of tumor & eventual dissemination of neoplastic mast cellsInternal dissemination of malignant tumor in following organs regional lymph nodes, spleen, liver, kidneys, lungs & heart

PrognosisIt is estimated that 50% of surgically removed mast cell tumors will re-grow in the same area.Prognosis is variable and depends on many factors including tumor location, histological grade and clinical stage

Jejunum of dog. Tumor cells are diffusely invading from the mucosal cell layer to the serosa. Mucosal ulceration is visible with tumor cell infiltration. HE.

Stomach of dog Slight pleomorphic tumor cells include round to ovoid nuclei with some pleomorphism. Numerous mitotic figures are visible (arrows). HE.

Monotonous population of mast cells with centrally located hyperchromatic nuclei and few discernable cytoplasmic granules. (HE, 10X)

Boxer:-Mast cell tumor, well differentiated, Wright-Leishman stain. Well differentiated mast cells have numerous, purple, cytoplasmic granules that partially obscure nuclear morphology.

Cutaneous mast cell tumor (well differentiated), dog, Wright-Leishman stain. The mast cells have numerous purple granules that partially obscure nuclear morphology

Well differentiated mast cells, cutaneous neoplasm, dog, Wright-Leishman stain. The neoplastic cells are of relatively uniform size and appearance with numerous fine purple granules.

Well differentiated cutaneous mast cell tumor, dog, hematoxylin & eosin stain. The mast cells have a relatively uniform appearance with heavy cytoplasmic granulation.

Intermediate differentiation, cutaneous mast cell tumor, dog, hematoxylin & eosin stain. The mast cells exhibit mild anisocytosis, anisokaryosis, decreased granulation, and increased mitotic activity

Well differentiated cutaneous mast cell tumor, dog, AgNOR stain. The mast cells have 1-2 AgNORs per cell with an overall score of 1.8. The potential for metastasis is low.

Intermediate differentiation, cutaneous mast cell tumor, dog, AgNOR stain. The mast cells have 1-7 AgNORs per cell with an overall score of 3.19. The potential for metastasis is very high.

Intermediate differentiation of mast cells, cutaneous neoplasm, dog, Wright-Leishman stain. The mast cells are large with pleomorphic cytoplasmic granulation that varies in size and abundance.

Poorly differentiated mast cells, cutaneous neoplasm, dog, Wright-Leishman stain. The mast cell (left) is large and has sparse cytoplasmic granulation.

Boxer:-Mast cell tumor, poorly differentiated, Wright-Leishman stain. The cytoplasm contains fine but sparse purple granules. A few eosinophils also are present.

TreatmentSurgeryRadiation therapyCryosurgeryPhotodynamic therapyChemotherapy -Corticosteroids like prednisolone -Antihistaminic drugs -antitumor drugs likes Vinblastine, vincristine

Mastocytoma in catTwo forms:- 1. Cutaneous/skin MCT 2. Histiocytic/visceral MCT

IncidenceSecond most common skin tumor (20% of all skin tumors)Age:- 10 years Breed:- Siamese catsSex:- Male>Female

Sites & gross morphologyHead & neck region more commonTwo type cutaneous growths:- 1. Firm 2. Diffuse

Multiple mast cell tumors in the skin of a cat with the visceral form of mast cell tumor disease

Multiple mast cell tumors all over their body

Histologic featuresSame to dogSome confusion between mastocytoma & eosinophilic granuloma complexSkin & oral cavity diffuse infiltration of eosinophiles & some extent mast cells in some lesions is called as eosinophilic granuloma complex

Growth & metastasisPotentially malignant than dog50% primary cutaneous mastocytoma involvement of regional lymph node & liver, spleen & other visceral organs

Haired skin of cat:- Endocytosis of erythrocytes by neoplastic mast cells

Lymph node, cat, Wright-Leishman stain. Metastatic mast cells exhibit anisocytosis and anisokaryosis with a variable degree of fine metachromatic granulation.

Mastocytoma of horse

Classification & incidenceTwo distinct form 1. Single cutaneous nodule 2. Disseminated multiple focal mast cell lesion in skinAge:- 7years Sex:- Male > FemaleBreed:- No predispose

Site & gross morphologyAny where in body but more in head2 to 20 cm diameterTumor confined to skinSurface normal appearance, hairless or ulcerated

Histological features Variable sized aggregates of well differentiated mast cellsMitotic figures are rareMature eosinophiles are local or diffuse accumulationCharacteristic feature is focal area of necrosis contained eosinophiles & necrotic debris

Etiology, transmission & metastasisUnknownOnchocerca spp. microfilariaeNo transmission occursMetastasis not reported

Mastocytoma of cattle, Sheep & pig

Cattle3% Of all cutaneous & subcutaneous tumorsNo any age, breed & sex predilection1 to 10 cm diameterAggregates of mast cell in regional lymph node, spleen, liver, lungs, heart & kidneysAlso occurs in internal organs ( omentum, abomasum, tongue) without cutaneous involvementMicroscopically similar to other spp.

PigAge:- 6 to 18 monthLimited to skin single or multipleNo metastasis

SheepVary little information regarding mastocytoma

Mast cell leukemia/Mstosarcoma

Primarily in cat with involvement of bone marrow, blood & spleenAge:- >8yearsSex:- Male>FemaleSplenomegaly (splenicmastocytosis), anemia, vomiting, GIT hyperirritabilityMost notable gross lesion in cat are hugely enlarged chocolate brown spleen, wider spread small pale focai on liver, gastric & duodenal ulcer.Diagnosis based on presence of mast cell in smear from blood & bone marrowMast cell 20u in diameter & round, centrally or eccentrically placed nucleus & cytoplasm packed with small, uniform, purple granules

Spleen, dog, Wright-Leishman stain. Two metastatic mast cells with coarse purple granules are present

Bone marrow, dog, Wright-Leishman stain. Metastatic mast cells exhibit anisocytosis and anisokaryosis.

Blood smear, dog, mast cell leukemia, Wright-Leishman stain. Cutaneous neoplasms were not present.

Blood smear, dog, Wright-Leishman stain. Mast cell is present in the blood smear of a dog with cutaneous neoplasms.

Blood smear, dog, Wright-Leishman stain. A degranulated mast cell (right) is present in the blood smear of a dog with systemic mastocytosis.

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